cursor collection::distinct(bsoncxx::string::view_or_value field_name, view_or_value query,
const options::distinct& options) {
bsoncxx::builder::stream::document command_builder{};
command_builder << "distinct" << name() << "key" << field_name.view() << "query"
<< bsoncxx::types::b_document{query};
if (options.max_time()) {
command_builder << "maxTimeMS" << options.max_time()->count();
}
scoped_bson_t command_bson{command_builder.extract()};
auto database = libmongoc::client_get_database(_get_impl().client_impl->client_t,
_get_impl().database_name.c_str());
auto result = libmongoc::database_command(database, MONGOC_QUERY_NONE, 0, 0, 0,
command_bson.bson(), NULL, NULL);
return cursor(result);
}
cursor collection::distinct(bsoncxx::string::view_or_value field_name,
view_or_value query,
const options::distinct& options) {
//
// Construct the distinct command and options.
//
bsoncxx::builder::basic::document command_builder;
command_builder.append(kvp("distinct", name()),
kvp("key", field_name.view()),
kvp("query", bsoncxx::types::b_document{query}));
if (options.max_time()) {
command_builder.append(
kvp("maxTimeMS", bsoncxx::types::b_int64{options.max_time()->count()}));
}
bsoncxx::builder::basic::document opts_builder{};
if (options.collation()) {
opts_builder.append(kvp("collation", *options.collation()));
}
const mongoc_read_prefs_t* rp_ptr = NULL;
if (options.read_preference()) {
rp_ptr = options.read_preference()->_impl->read_preference_t;
}
//
// Send the command and validate the reply.
//
scoped_bson_t reply;
reply.flag_init();
bson_error_t error;
scoped_bson_t command_bson{command_builder.extract()};
scoped_bson_t opts_bson{opts_builder.extract()};
auto result = libmongoc::collection_read_command_with_opts(_get_impl().collection_t,
command_bson.bson(),
rp_ptr,
opts_bson.bson(),
reply.bson(),
&error);
if (!result) {
throw_exception<operation_exception>(error);
}
//
// Fake a cursor with the reply document as a single result.
//
auto fake_db_reply = make_document(
kvp("ok", 1), kvp("cursor", [&reply](sub_document sub_doc) {
sub_doc.append(
kvp("ns", ""), kvp("id", 0), kvp("firstBatch", [&reply](sub_array sub_arr) {
sub_arr.append(reply.view());
}));
}));
bson_t* reply_bson =
bson_new_from_data(fake_db_reply.view().data(), fake_db_reply.view().length());
if (!reply_bson) {
throw bsoncxx::exception{bsoncxx::error_code::k_internal_error};
}
cursor fake_cursor{
libmongoc::cursor_new_from_command_reply(_get_impl().client_impl->client_t, reply_bson, 0)};
if (libmongoc::cursor_error(fake_cursor._impl->cursor_t, &error)) {
throw_exception<operation_exception>(error);
}
return fake_cursor;
}